package graph

import (
	"context"
	"fmt"
	"log/slog"

	"gitlab.com/unboundsoftware/eventsourced/eventsourced"

	"gitea.unbound.se/unboundsoftware/schemas/cache"
	"gitea.unbound.se/unboundsoftware/schemas/graph/model"
	"gitea.unbound.se/unboundsoftware/schemas/middleware"
	"gitea.unbound.se/unboundsoftware/schemas/sdlmerge"
)

//go:generate go run github.com/99designs/gqlgen
//go:generate gofumpt -w .
//go:generate goimports -w -local gitea.unbound.se/unboundsoftware/schemas .

// This file will not be regenerated automatically.
//
// It serves as dependency injection for your app, add any dependencies you require here.

type Publisher interface {
	Publish(ctx context.Context, event eventsourced.Event) error
}

type Resolver struct {
	EventStore     eventsourced.EventStore
	Publisher      Publisher
	Logger         *slog.Logger
	Cache          *cache.Cache
	PubSub         *PubSub
	CosmoGenerator *CosmoGenerator
	Debouncer      *Debouncer
}

func (r *Resolver) apiKeyCanAccessRef(ctx context.Context, ref string, publish bool) (string, error) {
	key, err := middleware.ApiKeyFromContext(ctx)
	if err != nil {
		return "", err
	}
	apiKey := r.Cache.ApiKeyByKey(key)
	if publish && !apiKey.Publish {
		return "", fmt.Errorf("provided API-key doesn't have publish privilege")
	}
	if !publish && !apiKey.Read {
		return "", fmt.Errorf("provided API-key doesn't have read privilege")
	}
	for _, rr := range apiKey.Refs {
		if rr == ref {
			return apiKey.Name, nil
		}
	}
	return "", fmt.Errorf("provided API-key doesn't have the required privilege on the requested Schema Ref")
}

func (r *Resolver) handler(ctx context.Context, aggregate eventsourced.Aggregate) (eventsourced.CommandHandler, error) {
	return eventsourced.NewHandler(ctx, aggregate, r.EventStore, eventsourced.WithEventPublisher(r.Publisher))
}

func apiKeyId(orgId, name string) string {
	return fmt.Sprintf("%s-%s", orgId, name)
}

// WarmCache precomputes the merged SDL and SchemaUpdate (cosmo router
// config) for every (orgId, ref) tracked in the cache. Intended to run
// once at startup, after the event-sourced caches have been populated
// but before the pod accepts traffic, so the first request per ref does
// not pay the cold-start cost of running sdlmerge + wgc compose.
//
// Errors per ref are logged and skipped rather than aborting the whole
// warmup: a single bad ref must not block the pod from serving the
// remaining refs.
func (r *Resolver) WarmCache(ctx context.Context) {
	refs := r.Cache.AllOrgRefs()
	r.Logger.Info("Warming schema cache on startup", "refCount", len(refs))

	for _, or := range refs {
		services, lastUpdate := r.Cache.Services(or.OrgId, or.Ref, "")
		if len(services) == 0 {
			continue
		}

		subGraphs := make([]*model.SubGraph, len(services))
		serviceSDLs := make([]string, len(services))
		for i, id := range services {
			sg, err := r.fetchSubGraph(ctx, id)
			if err != nil {
				r.Logger.Error("warmup: fetch subgraph", "error", err, "orgId", or.OrgId, "ref", or.Ref, "id", id)
				subGraphs = nil
				break
			}
			subGraphs[i] = r.toGqlSubGraph(sg)
			serviceSDLs[i] = sg.Sdl
		}
		if subGraphs == nil {
			continue
		}

		if sdl, err := sdlmerge.MergeSDLs(serviceSDLs...); err != nil {
			r.Logger.Error("warmup: merge SDLs", "error", err, "orgId", or.OrgId, "ref", or.Ref)
		} else {
			r.Cache.SetMergedSDL(or.OrgId, or.Ref, lastUpdate, sdl, subGraphs)
		}

		cosmoConfig, err := r.CosmoGenerator.Generate(ctx, subGraphs)
		if err != nil {
			r.Logger.Error("warmup: generate cosmo config", "error", err, "orgId", or.OrgId, "ref", or.Ref)
			continue
		}
		r.Cache.SetSchemaUpdate(or.OrgId, or.Ref, &model.SchemaUpdate{
			Ref:               or.Ref,
			ID:                lastUpdate,
			SubGraphs:         subGraphs,
			CosmoRouterConfig: &cosmoConfig,
		})
	}

	r.Logger.Info("Schema cache warmup complete", "refCount", len(refs))
}